Mon Mar 9 15:40:50 2020 UTC ()

external/cddl/osnet: Fix possible null pointer access.

Detected by UBSan and fixed upstream, pick only the fix from the commit.

Cherry-pick:
From 928e8ad47d3478a3d5d01f0dd6ae74a9371af65e Mon Sep 17 00:00:00 2001
From: Serapheim Dimitropoulos <serapheimd@gmail.com>
Date: Wed, 20 Feb 2019 09:59:57 -0800
Subject: [PATCH] Introduce auxiliary metaslab histograms

Reviewed by: Paul Dagnelie <pcd@delphix.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matt Ahrens <mahrens@delphix.com>
Signed-off-by: Serapheim Dimitropoulos <serapheim@delphix.com>
Closes #8358

Reviewed by: kamil@


(fox)

diff -r1.1.1.3 -r1.2 src/external/cddl/osnet/dist/uts/common/fs/zfs/metaslab.c

--- src/external/cddl/osnet/dist/uts/common/fs/zfs/metaslab.c 2018/05/28 20:52:58	1.1.1.3
+++ src/external/cddl/osnet/dist/uts/common/fs/zfs/metaslab.c 2020/03/09 15:40:50	1.2

 @@ -3360,27 +3360,27 @@ metaslab_class_throttle_unreserve(metasl
 	mutex_enter(&mc->mc_lock);
 	for (int d = 0; d < slots; d++) {
 		(void) refcount_remove(&mc->mc_alloc_slots, zio);
+	}
 	mutex_exit(&mc->mc_lock);
+}
 int
 metaslab_alloc(spa_t *spa, metaslab_class_t *mc, uint64_t psize, blkptr_t *bp,
     int ndvas, uint64_t txg, blkptr_t *hintbp, int flags,
     zio_alloc_list_t *zal, zio_t *zio)
+{
 	dva_t *dva = bp->blk_dva;
-	dva_t *hintdva = hintbp->blk_dva;
+	dva_t *hintdva = (hintbp != NULL) ? hintbp->blk_dva : NULL;
 	int error = 0;
 	ASSERT(bp->blk_birth == 0);
 	ASSERT(BP_PHYSICAL_BIRTH(bp) == 0);
 	spa_config_enter(spa, SCL_ALLOC, FTAG, RW_READER);
 	if (mc->mc_rotor == NULL) {	/* no vdevs in this class */
 		spa_config_exit(spa, SCL_ALLOC, FTAG);
 		return (SET_ERROR(ENOSPC));
+	}
 	ASSERT(ndvas > 0 && ndvas <= spa_max_replication(spa));